Bell labs was the first to propose
a cellular network in 1947. It was a network of small overlapping
cell sites with a call switching infrastructure that tracked users
as they moved through a network and pass their calls from one
network to another without dropping their calls.The first commercial
cellular network was in the 1970's in chicago. By 2007 the number of
cell phones in the world reached 3.3 billion people. In 1996 Nokia
was the first to enable internet connectivity and wireless email
they called these cell phones smart phones.
